diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp
--- a/llvm/lib/Transforms/IPO/Inliner.cpp
+++ b/llvm/lib/Transforms/IPO/Inliner.cpp
@@ -158,10 +158,6 @@
                    "<Line Number>:<Column Number>.<Discriminator> (default)")),
     cl::desc("How cgscc inline replay file is formatted"), cl::Hidden);
 
-static cl::opt<bool> InlineEnablePriorityOrder(
-    "inline-enable-priority-order", cl::Hidden, cl::init(false),
-    cl::desc("Enable the priority inline order for the inliner"));
-
 LegacyInlinerBase::LegacyInlinerBase(char &ID) : CallGraphSCCPass(ID) {}
 
 LegacyInlinerBase::LegacyInlinerBase(char &ID, bool InsertLifetime)
@@ -781,12 +777,7 @@
   // this model, but it is uniformly spread across all the functions in the SCC
   // and eventually they all become too large to inline, rather than
   // incrementally maknig a single function grow in a super linear fashion.
-  std::unique_ptr<InlineOrder<std::pair<CallBase *, int>>> Calls;
-  if (InlineEnablePriorityOrder)
-    Calls = std::make_unique<PriorityInlineOrder<InlineSizePriority>>();
-  else
-    Calls = std::make_unique<DefaultInlineOrder<std::pair<CallBase *, int>>>();
-  assert(Calls != nullptr && "Expected an initialized InlineOrder");
+  DefaultInlineOrder<std::pair<CallBase *, int>> Calls;
 
   // Populate the initial list of calls in this SCC.
   for (auto &N : InitialC) {
@@ -801,7 +792,7 @@
       if (auto *CB = dyn_cast<CallBase>(&I))
         if (Function *Callee = CB->getCalledFunction()) {
           if (!Callee->isDeclaration())
-            Calls->push({CB, -1});
+            Calls.push({CB, -1});
           else if (!isa<IntrinsicInst>(I)) {
             using namespace ore;
             setInlineRemark(*CB, "unavailable definition");
@@ -815,7 +806,7 @@
           }
         }
   }
-  if (Calls->empty())
+  if (Calls.empty())
     return PreservedAnalyses::all();
 
   // Capture updatable variable for the current SCC.
@@ -841,15 +832,15 @@
   SmallVector<Function *, 4> DeadFunctionsInComdats;
 
   // Loop forward over all of the calls.
-  while (!Calls->empty()) {
+  while (!Calls.empty()) {
     // We expect the calls to typically be batched with sequences of calls that
     // have the same caller, so we first set up some shared infrastructure for
     // this caller. We also do any pruning we can at this layer on the caller
     // alone.
-    Function &F = *Calls->front().first->getCaller();
+    Function &F = *Calls.front().first->getCaller();
     LazyCallGraph::Node &N = *CG.lookup(F);
     if (CG.lookupSCC(N) != C) {
-      Calls->pop();
+      Calls.pop();
       continue;
     }
 
@@ -865,8 +856,8 @@
     // We bail out as soon as the caller has to change so we can update the
     // call graph and prepare the context of that new caller.
     bool DidInline = false;
-    while (!Calls->empty() && Calls->front().first->getCaller() == &F) {
-      auto P = Calls->pop();
+    while (!Calls.empty() && Calls.front().first->getCaller() == &F) {
+      auto P = Calls.pop();
       CallBase *CB = P.first;
       const int InlineHistoryID = P.second;
       Function &Callee = *CB->getCalledFunction();
@@ -950,7 +941,7 @@
           }
           if (NewCallee) {
             if (!NewCallee->isDeclaration()) {
-              Calls->push({ICB, NewHistoryID});
+              Calls.push({ICB, NewHistoryID});
               // Continually inlining through an SCC can result in huge compile
               // times and bloated code since we arbitrarily stop at some point
               // when the inliner decides it's not profitable to inline anymore.
@@ -985,7 +976,7 @@
       if (Callee.isDiscardableIfUnused() && Callee.hasZeroLiveUses() &&
           !CG.isLibFunction(Callee)) {
         if (Callee.hasLocalLinkage() || !Callee.hasComdat()) {
-          Calls->erase_if([&](const std::pair<CallBase *, int> &Call) {
+          Calls.erase_if([&](const std::pair<CallBase *, int> &Call) {
             return Call.first->getCaller() == &Callee;
           });
           // Clear the body and queue the function itself for deletion when we
diff --git a/llvm/test/Transforms/Inline/inline_call.ll b/llvm/test/Transforms/Inline/inline_call.ll
--- a/llvm/test/Transforms/Inline/inline_call.ll
+++ b/llvm/test/Transforms/Inline/inline_call.ll
@@ -1,6 +1,5 @@
 ; Check the optimizer doesn't crash at inlining the function top and all of its callees are inlined.
 ; RUN: opt < %s -O3 -S | FileCheck %s
-; RUN: opt < %s -O3 -inline-enable-priority-order=true -S | FileCheck %s
 
 define dso_local void (...)* @second(i8** %p) {
 entry:
diff --git a/llvm/test/Transforms/Inline/inline_invoke.ll b/llvm/test/Transforms/Inline/inline_invoke.ll
--- a/llvm/test/Transforms/Inline/inline_invoke.ll
+++ b/llvm/test/Transforms/Inline/inline_invoke.ll
@@ -1,6 +1,5 @@
 ; RUN: opt < %s -inline -S | FileCheck %s
 ; RUN: opt < %s -passes='cgscc(inline)' -S | FileCheck %s
-; RUN: opt < %s -passes='cgscc(inline)' -inline-enable-priority-order=true -S | FileCheck %s
 
 ; Test that the inliner correctly handles inlining into invoke sites
 ; by appending selectors and forwarding _Unwind_Resume directly to the
diff --git a/llvm/test/Transforms/Inline/last-callsite.ll b/llvm/test/Transforms/Inline/last-callsite.ll
--- a/llvm/test/Transforms/Inline/last-callsite.ll
+++ b/llvm/test/Transforms/Inline/last-callsite.ll
@@ -1,5 +1,4 @@
 ; RUN: opt < %s -passes='cgscc(inline)' -inline-threshold=0 -S | FileCheck %s
-; RUN: opt < %s -passes='cgscc(inline)' -inline-threshold=0 -inline-enable-priority-order=true -S | FileCheck %s
 
 ; The 'test1_' prefixed functions test the basic 'last callsite' inline
 ; threshold adjustment where we specifically inline the last call site of an